1. Field of the Invention
This invention relates generally to treatment of solid cancers. More particularly, the invention relates to a charged particle cancer therapy dose distribution method and apparatus optionally used in combination with beam injection, acceleration, extraction, and/or targeting methods and apparatus.
2. Discussion of the Prior Art
Cancer
Proton therapy systems typically include: a beam generator, an accelerator, and a beam transport system to move the resulting accelerated protons to a plurality of treatment rooms where the protons are delivered to a tumor in a patient's body.
Proton therapy works by aiming energetic ionizing particles, such as protons accelerated with a particle accelerator, onto a target tumor. These particles damage the DNA of cells, ultimately causing their death. Cancerous cells, because of their high rate of division and their reduced ability to repair damaged DNA, are particularly vulnerable to attack on their DNA.
Due to their relatively enormous size, protons scatter less easily than X-rays or gamma rays in the tissue and there is very little lateral dispersion. Hence, the proton beam stays focused on the tumor shape without much lateral damage to surrounding tissue. All protons of a given energy have a certain range, defined by the Bragg peak, and the dosage delivery to tissue ratio is maximum over just the last few millimeters of the particle's range. The penetration depth depends on the energy of the particles, which is directly related to the speed to which the particles were accelerated by the proton accelerator. The speed of the proton is adjustable to the maximum rating of the accelerator. It is therefore possible to focus the cell damage due to the proton beam at the very depth in the tissues where the tumor is situated. Tissues situated before the Bragg peak receive some reduced dose and tissues situated after the peak receive none.
Problem
There exists in the art of charged particle irradiation therapy a need for efficient, even, accurate, and precise delivery of Bragg profile energy to a tumor. More particularly, there exists a need to deliver an effective and uniform radiation dose to all positions of a tumor while minimizing radiation dosage to surrounding tissue. Still further, there exists a need in the art to control the charged particle cancer therapy system in terms of patient translation position, patient rotation position, specified energy, specified intensity, and/or timing of charged particle delivery relative to a patient position. Preferably, the system would operate in conjunction with a negative ion beam source, synchrotron, and/or targeting method apparatus.